4 lb Chuck Eye Roast, or other chuck roast, tied
Kosher Salt, freshly ground Black Pepper
Flour, for dusting
2 Tbsp Extra-Virgin Olive Oil
4 lg Ancho Chilies, steamed and seeded
1 lg Onion, coarsely chopped
3 cloves Garlic
4 cups Beef Stock, or low sodium broth
6 Thyme sprigs, 6 Parsley sprigs, and 2 Bay Leaves, tied
1 1/2 lbs Yukon Gold potatoes, peeled and cut into 2-inch chunks
1 1/2 tsp Corn Starch, mixed with 2 Tbsp Water
Preheat oven to 300'. Season the roast with salt and pepper and dust with flour. In a medium, enameled cast iron pot, heat 2 Tbsp of olive oil. Add the roast; cook over moderate heat, turning, until browned all over, 20 minutes. Transfer to a plate.
Meanwhile soak the Ancho chilies in 1/2 cup boiling water for 20 minutes. In a food processor or blender, puree the chilies with their liquid.
Add the onion and garlic to the pot and cook, stirring, until softened, 5 minutes. Add the chili puree, stock, and herb bundle and bring to a boil. Return the meat to the pot, cover and transfer to the oven. Braise for 2 1/2 hours or until tender, turning once halfway through.
Transfer the roast to a plate. Strain the cooking liquid into a bowl, discard the solids. Skim off the fat and return the liquid and meat to the pot. Add the potatoes. Cover and braise in the oven for 30 minutes, until the potatoes are tender.
Transfer the roast to a work surface. Using a slotted spoon, transfer the potatoes to a deep serving platter; cover. Boil the liquid until reduced to 3 1/2 cups. Stir the cornstarch slurry and whisk it into the simmering liquid until thickened.
Remove the strings from the roast and cut into thick slices; arrange on the platter and pour the sauce on top.